"Whether it's Manhattan, the Hamptons, Miami, Los Angeles, we're seeing the inventory fall sharply," said real estate expert Jonathan Miller.
People may want a bigger home, "but you don't have things to buy," said Miller. "You don't have the selection."
The scarce supply is what keeps Shannon Mulvihill searching rigorously for new listings for three-bedrooms for sale for her family.
"I think there are so few available it makes sense to look when they come to the market," she said. "You know there's a risk if you don't put an offer in, that somebody else could get it."
Experts say the inventory problem extends to red-hot neighborhoods like Hell's Kitchen. It's being attributed to a slowdown in new construction projects in the still sluggish economy.
Stephen Kliegerman of Halstead Property said the next trend could be eager consumers buying from blueprints before they've even seen the finished apartment, although Kliegerman admits it could be "a little scary for some buyers because they don't know what the quality of the product's going to be."
Still, some experts say renters could be in a surprisingly strong position, especially if they stay put for just another year because there's expected to be a construction boom in 12 to 18 months that should add inventory and give renters more flexibility to negotiate.
Mulvihill and her husband don't want to keep renting while interest rates are so low.
"It's always appealing to think you can actually own with more space versus renting right now," said Mulvihill.
So she'll keep looking and perhaps take a risk -- what some experts call the sign of a healthier real estate market.